As an enhanced filter for a network device, the DPI (Deep Packet Inspection, deep packet inspection) technology gradually and organically integrates capabilities such as user management, security control, and fine service control, to implement functions such as dynamic awareness, policy control, and QoS (Quality of Service, quality of service) assurance for varied services, and security assurance for networks and services, thereby reducing capital expenditure and operating expenditure of a telecom operator and providing a basic operation platform of telecommunications services for the telecom operator.
A basic principle of the DPI technology includes: detecting certain feature characters in a high-layer protocol (for example, the application layer) in a packet, and then performing matching with a state machine (formed by compiling a rule), determining that the detected feature characters are some predetermined keywords, and performing corresponding processing according to a determination result.
The DPI technology may be implemented based on software or hardware. Software implementation is relatively flexible, but performance is poor (with, for example, a low speed low and a small number of supported rules). In an actual application, to enhance the performance, hardware is generally adopted for implementation in the prior art. For example, a FPGA (Field-Programmable Gate Array, field-programmable gate array) is used for implementation. However, to enable a product to achieve better performance improvement, finding a better method to improve performance is an issue to be solved in the industry.